Currently, the simulated user calling performance test for digital SPC switch mainly employs large traffic call test instruments. In the market, there are a lot of commercial simulated user calling test instruments to be selected. Such test instrument is characterized in simulating the calling process of actual user realistically, in which the test is performed by transmitting and receiving pass detecting tone and judging the pass detecting tone while a call is initiated on an user line, a dial is simulated and the called is communicated, and, therefore, it can realistically reflect the processing on calls by the switch system and its performance on the call processing. However, they are not applied in many institutes because of their high prices. Therefore, in the actual operation of a network, branches of many operators do not buy this kind of equipment, and, consequently, calling tests are very complicated during pass tests of many digital SPC switches. If there is a calling test instrument built-in the switch, the test will be simpler.
In the China patent application No. 99116068.1, a simulating caller is disclosed, in which its all parts are installed in a switch. This patent application realized an independent simulated calling test instrument, which can not be built in digital SPC switch system.
In actual application, there has already been a kind of switch with a built-in large traffic calling test system, in which it is characterized in that it designs a virtual calling process on a user element processor, simulating the whole process including initiating a call by a user and answering by the called user the call. But the main disadvantage of this kind of system is that it can only realistically test the process of call signaling by the main control system in the tested switch, but not the performances such as the hardware interface performance in the switch and the performance of the switch connection path, and actually, it can not accurately reflect the call process performance of the switch system.